DE1443197A1 - Fluorination process - Google Patents

Description

PATENTAN WAL ι c DR. W. SCHALK DIPL-ING. PETER WlRTH 144319 ' DIPL.-ING. G. E. M. DANNENBERG · DR. V. SCHMIED-KOWARZIK FRANKFURT AM MAIN OR. IICHINHIIMII "T". «9

0-2986-C Nov 6, 1961

SK / Ka.

Onion Carbide Corporation

270, Park Avenue New York 17, N.Y./IJSA

Fluo * ation process

(Addition to patent application (u 7986) - Ψ ^^ 3 ^Α ^ Ύ ^ι

The present invention relates to a process for the preparation of perchlorofluoropropanes, and in particular it relates to the vapor phase fluorination of 1,1,1,3,3 _f 3-hexachloro-2,2-difluoropropane and the partially fluorinated derivatives of this compound. Furthermore, the present invention provides an economical process for the production of 1,3-dichlorohexafluoropropane and 1-chloroheptafluoropropane

{The fluorination process according to the invention is characterized in that a mixture of 1,1,1,3 % 3 »3-hexachloro-2,2-difluoropropane and hydrogen fluoride in the presence of a chromium-Pluorierungskatalyeatora at a temperature of 200 to 500 °

• heated and the resulting mixture of 1,3-Diohlorhexafluorpropane and 1-chloroheptafluoropropane and the obtained fluorination intermediates separates

;? i 809812 / U15 " ² "''

ι ■ "■» ■ '·

The inventive method can either batch or be carried out continuously. In one method, the reaction mixture is continuously passed over in the form of a vapor passed the chromium-pluorization catalyst, which is in a tubular reaction vessel made of stainless steel or nickel is located. The outflowing gaseous product mixture is showered passed a water washer and dryer and then condensed and recovered. The individual components of the Product mixtures are expediently separated from one another by distillation separated.

The treatment temperature can vary between 200 and 500 ° and is preferably between 300 and 400 ° "A reaction temperature of about 350 is particularly suitable" at temperatures of less than 200, only slight conversions are achieved, and temperatures of more than 400 promote cleavage of the Carbon bonds and shorten «the effectiveness of the catalyst.

The inventive method can both at atmospheric Pressure as well as negative or positive pressure can be carried out * A Übordruek 'is particularly useful when by distillation anhydrous hydrogen fluoride and hydrogen chloride should be. The applied pressure can be up to 21 kg / cm or be more *

809812 / H1S

The residence time of the boiling mixture in the reaction vessel depends to a large extent on the reaction temperature and the proportions of the individual components desired in the product mixture away. It can take between 1 second at the higher temperatures

or longer
and fluctuate several minutes / at the lower temperatures.

In a typical reaction sequence, the vapor residence time in the reaction vessel is 1 to 10 seconds at one reaction temperature between 200 and 500 ° * A residence time of 2 to 5 seconds at temperatures between 300 and 400 °.

The taolar ratio of hydrogen fluoride to that of the starting material Halocarbon used in the feed can be between 1 and 12 moles of hydrogen fluoride per mole of halocarbon vary and is preferably 4 to 10 moles of hydrofluoric acid per mole of halocarbon material. The per mole of halocarbon The amount of hydrogen fluoride required depends on both the fluorine content of the desired product and the fluorine content of the halogenated carbon used.

The inventive fluorination of 1 _s 1,1 »3» 3f3-hexachloro-2,2-difluoropropane and the partially fluorinated derivatives of this compound yields a product mixture which generally contains 1,3-diohlorliexafluoropropane as the main constituents. In addition, the product mixture contains I-chlorheptafluoropropane and JiluorierUn ^ B intermediates, such as 1,1,1 jJ ^ -pentachlorotrifluoropropane, 1,1,3 | 3-tetradilortetrafluoropropane and 1,1,3-

8 0 9 8 1 2 / U 1 5 _ ₄ _

Trichloropentafluoropropane. The complete absence of isomers of these fluorination products is an unexpected and surprising one Feature of the method according to the invention.

The reaction conditions can be controlled so that each of the above five fluorinated derivatives can be obtained as the major product · The fluorinated intermediates can be used as feed in the R ^- Saf ions zone are recycled to prepare the highly fluorinated derivatives.

The chromium fluorination catalyst can be used in various forms. For example, the catalyst can be in the form of grained ^ hydrated chromium oxide (Cr ₂ O ,. χ HgO), which by the action of ammonium hydroxide on an aqueous chromium chloride solution or another aqueous solution of a water-soluble salt, such as chromium nitrate, is obtained as a precipitate. The same hydrated chromium oxide can also be used in the form of small cubes, which are made from a partially dried paste of the above-mentioned precipitate. Furthermore, the hydrated chromium oxide can be mixed with a small amount of chromium chloride and processed into tablets. The chromium chloride in the mixture acts as a lubricant and makes processing into tablets easier. In addition, chromium chloride and aluminum chloride can be precipitated together with ammonium hydroxide. The precipitate obtained in this way can also be in the form of grains, small cubes or tablets

8 0 9812/1415

ORlGiNALiNSPBCTED

can be applied. In a further embodiment, the chromium oxide is applied to an alumina carrier. The chromium oxide catalysts produced in the following manner and applied to alumina are particularly preferred. Porous alumina is impregnated with an aqueous solution of chromium trioxide (CrO ~) Reduced temperature in a hydrogen atmosphere. Either ^ k-alumina or the activated types, such as, for example, Ϋ- alumina, P * -Alumina, »^ -Alumina or the like, can be used as the porous alumina. According to the invention, chromium oxide catalysts and in particular the chromium oxide catalysts applied to alumina are preferred.

To obtain the products fluorinated according to the invention, the outflowing (Jas washed with water, with a Trooimittel, such as silica gel, activated alumina or a molecular sieve, dried and then condensed and separated. the

distilled product mixture is fractionated around the individual components the same to be separated j if necessary, one or more constituents of the product mixture can be returned to the system /will. This process can easily be adapted for industrial use by using suitable cooling and pressure equipment. -gen be provided to the required separation and recycling processes perform.

The preferred starting material is 1,1,1,3,3,3-hexachlo »4ifluoropropane is obtained by photochlorination of 2,2-difluoropropane »rhaltm» ·

8098t2 / Ui5 -6-

According to the invention, 1,5-dichlorohexafluoropropane and partially fluorinated intermediates in high yields and good efficacy ■

sam
a # & a £ * iiekkeit from readily available, cheap raw materials

getting produced. The reaction conditions can be set by organizing

in the desired. Area .

niche heat transfer media / to be maintained and managed Avoid excessive corrosion of the metal device

1,5-dichlorohexafluoropropane and 1-chloroheptafluoropropane are extremely stable products of low toxicity which are useful as refrigerants, chemical intermediates, and the like. The obtained from the present invention obtained Produktmiachung _f partially fluorinated intermediates are good solvents, hydraulic fluids, heat transfer media and dielectric Flüss'igkeiten.

The following examples serve to explain the process according to the invention.

Example 1:

This example illustrates the production of the invention

required chromium catalysts. ·

(a) There were 1145 ecm of water and 588 g of ammonium hydroxide

(28 fo NH ^) placed in a flask fitted with a mechanical stirrer and a dropping funnel. Inner

Half of 1 hour, a chromium chloride solution (520 g of a 37% chromium chloride solution and 1 1 water) with stirring in dropped the flask. The precipitate obtained was from the Separated supernatant liquid and washed with water to remove the Annnoniumohlorida. Then the precipitate became put in a shallow bowl and. at 70 ° in a yakuum oven dried. Once the material was partially dry, the paste was cut into small cubes so that the hydrated Chromium oxide catalyst was present after complete drying in the form of about 0.6 cm large cubes * The final Drying of the hydrated chromium oxide catalyst was at 480 performed under a nitrogen atmosphere.

(b) About 600 ecm (247 g) of hydrated chromium oxide were obtained, which had been prepared as described under (a), mixed with 45 g of anhydrous chromium chloride and the mixture for 16 hours grind in a ball mill. The fine powder thus obtained was molded using molds with an opening of about 2.4 mm processed into beads.

(o) There was about 344 g (2.5 moles) of aluminum chloride in 1.5 liters Dissolved in water. This solution was mixed with a solution containing 395 g (2.5 mol> Chromium nitrate contained in 3.67 1 liter. The resulting solution was placed in a flask with vigorous stirring given, which contained 920 g of 28 #iges ammonium hydroxide with 4 liters of water was diluted. The resulting precipitate was removed

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separates, and washed several times with water. Then the material was poured into shallow bowls, about 0.6 inch large cube cut up and first at 60 ° and then for two days at 450 ° in dried in an oven.

-Cd) - There were about 67.1 g of chromium trioxide (GrO ^) in 102 g of water solved. This solution was then slowly added with frequent stirring added to 300 com of activated clay (i ^ -form »6-8 mesh), the was in a vacuum flask. The material was partially dried by heating the flask under reduced pressure became. The contents of the flask would then be transferred to a nickel reactor

Inside-·
tion vessel with a diameter of 2.54 cm and heated to 200 ° under a constant stream of nitrogen in order to dry the catalyst completely. The orange-red catalyst was then reduced with hydrogen at 250 to 300 ° for 4 hours.

whereby a green chromoside catalyst (Cr-O *) on y * - was received »

■ - ■ -. ■■ © in. - -. ■ ■ - - In a similar® way, was® v® ^ »GhromQ ^ äkatalysator au £ ^, - clay-

earth produced ο This catalytic converter applied to A

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tor had particularly good mechanical strength. "\

Example 2>

chlorodifluoropropane.

■ ■ ■ "■■" ■, · ■ _9 <_

-, "■■■ -" ■ '■■ ORiGlNALiNSPECTED

809812 / U15 ^ - —- «

This example illustrates the preparation of 1,1,1,3 _r 3 _f 3-Hexa ~ j

(a) Production of 2,12-pifluoryropane

The hydrofluorination of propyne was carried out over a chromium oxide on alumina catalyst "Performed at a temperature of 350 Ms 400. The catalyst was located in a 5 cm χ 120 cm large tubular nickel reaction vessel heated with molten salt. Hydrogen fluoride and propyne vapors were in a molar ratio of 2.6-5.1 s 1.0 over the Catalyst passed · The one emerging from the heating vessel Gas was passed through a short copper tube immersed in a bath of solid carbon dioxide and acetone, and the liquid Condensate passed into a stainless steel container held at 25 to 50 degrees. The unreacted propyne and 2.]? fluoropropene obtained in the vapor phase reaction vessel reacted with the hydrogen fluoride in the liquid Haasa and produced 2,2-difluoropropane as the main product. the volatile products were removed by its water heater and • Drained a Trooknunga column filled with calcium chloride and in "cold" fall condensed. The condensate from the lall, was distilled / to small amounts of 2-Iluorpropaa and non-

/ umgeeetate »remove pröpin au · the one obtained as the main product a, 2-difluoropropane was found as a relatively pure! fraction with a

- boiling point! insulated from -2 to 0 °

above beeohrieben »Process for the production of 2,2-difluoropropane is superior to all previously known and practiced methods. The hydrofluorization of propine by means of the new process

. . 809812 / 1415- 9 ^raGINAL inspected.

■■ - ■■ - ίο - ■■ -, ■ · ..; .- ■■■;

rens is performed in two ways by adding a mixture = of propyne and hydrogen fluoride at a temperature between 75 and 400 °, preferably between 200 and 300 °, with a Chromium oxide catalyst is brought into contact. 1 to 5 moles of hydrogen fluoride can be used per mole of propyne, the preferred ratio being 2 to 4 moles of hydrogen fluoride per mole of propyne is »■.

Some known processes for making 2,2-difluoropropane are from A.L. Henne and M.W. Renoll in "Journal of the American Chemioal Society, 59% page 2434 (1937) and by A · V. Grosse and C.B. Linn in "Journal of the American Chemical Society, 64 ", p. 2289 (1942)

(b) The chlorination of 2,2-difluoropropane in the liquid phase was carried out at atmospheric pressure in a Pyresglas apparatus using ultraviolet lamps to catalyze the reaction. The feed material was placed in a flask which was cooled with a thermometer, a tube reaching below the liquid level for the introduction of the oil and a cooling device that was cooled with a mixture of carbonic acid and acetone _? * The cooling equipment was in connection with. a Wassarwaschanlag® ₉ . _; , a Calöiumohloriä-feockmmgslcelonn © unä lält © fall® Because © chlorine was ©. a Ζγ2ά && @ & durali äas- @ asein £ lihrimgsroiir in 'the flask / g @ l®itet> Di © aafäagliche "B @ aktlonst0mperätur" amount.

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-10 to 0 ° and was by the reflux from the with feeter Carbonated chilled. Regulated cooling device. A «only one Irradiation lamp (275 watts) was sufficient during the initial stages of the reaction; after half of the theoretically required Amount of. After chlorine had been introduced, two more lamps were placed to provide additional radiation and heat to deliver · The progress of the reaction was followed by adding dna water to the washing plant for its hydrogen chloride content was investigated. The 1 »1,1,5,3,3-HexachlcrIkfluoropropane was obtained in a throughput in yields of $ 85 to $ 90 *

Example 3? ,

This example explains the fluorination of 1> 191 * 5.3 »3-hexa-

chlorofluoropropane with hydrogen fluoride »

The vapor phosphate fluorination γοη 1 , 1,1,3 # 5 $ 3 «HexaohlordifXuorprcpan was iron in a Niokel reaction vessel with buckets of inner durometer. 2.94 om over 250 esm of a hydrated chromium oxide-on-alumina catalyst. The reaction test tubes were between 250 and 360 °. The hexaohlordifluoropropane and the hydrogen fluoride were evaporated over a catalyst or the residence times were 1.1 to 3.3 seconds. The water washing system was "

-12- 8ÖÖ612 / U15

provided with a decanter to remove the oil condensate to separate from the wash water. The water was collected and on his. Content of acid © and chloride ions investigated. These values enable a continuous determination of the

fluorination took place.

+ for the measure. ·

The product mixes were recovered and the ingredients the mixtures separated from one another by distillation. The substances boiling below 34 ° were collected and analyzed by gas chromatography analyzed.

The reaction conditions and the analyzes of the products obtained Twelve different approaches are outlined below ! Tables I and II recorded.

INSPECTED

- 13 - 80S8127U15

i
S. 809812 / U1 inaatz 5 1 • 2 I. 3 ■ 4 5 • 340-355 S. ■ 8th 6th f fiea3rtionat «ig? er8, tur, ⁰ C 330 ^ -350 350 ^ 355 350-355 * ■
340-355 T * 3 S. G 340-360 D «* er d.Anaata.a ,, Std · '^ ⁰ ' ,Tabel • Cf _t 5 4 * 5 • · 5 ·, 3-- 2770 S. • 5.4 ' Coverings 583 g / 1830 g 1688 g ' 2008 'g 1670 S. 2000 g 385 g 1226 'g • 995 p 1302 g 8.7 1307 g Molar * s BescMctamgsverh.
"JKol · HP / Mol C-CIgP- 9.5 11.3 *, 5 9.3 1.4 9.4 Touched for _y seconds 3.3 -2.5 1.4 1.5 6th 1.3 Lower boiling products δ g 48 g 31 g 3 g 1094 1 δ 289 g 1171 g 972 g 640 g 926 453 g 105 g ■ <49 g 68 g 830 g 82 971 g CCi ₂ PCP ₂ CGi ₂ P .— · - 67 g '0.3 152 g -., Yield and effectiveness 1.5 3.7 2.5 0.2 5r, 3 , 0.1 CCIP ₂ CP ₂ GClP ₂ , 56 64.5 83.0 75.0 41 ', 5 40.4 29.4 CCl ₂ PCP ₂ GOlP ₂₈ # 2t, 7 3.2 • 4.9 50.0 3.4 58.7 CCl ₀ PCP ₁₅ CCl ₀ P, 36
4C, JCa Cm. "LOfl 1.0 - - - - 3.8 37 8.6 Manufacturing ratio, ^ 24 31 54 30th 21 j

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Example 4:

This example illustrates the further fluorination of the intermediates, that in the fluorination of 1,1,1,3 »3» 3-hexaohlordifluoropropane were obtained.

(a) During a reaction time of 2.75 hours, 336 g 1,3-dichlorohexafluoropropane and 152 g of hydrogen fluoride in one Temperature of 450 ° in the manner described in Example 3 passed over 250 com of a * chromium oxide-on-alumina catalyst. Gas chromatography and mass spectral analysis of the condensate obtained showed that the product was 34 g of 1-chloroheptafluoropropane and 245 g of unreacted 1,3-dichlorohexafluoropropane as well Contained traces of perfluoropropane.

(b) During a reaction time of 2.6 hours, 418 g of 1,1,3-triochloropentafluoropropane and 188 g of hydrogen fluoride were such as as described above, passed over a chromium oxide catalyst at 350 ° Distillation and analysis of the product obtained showed that it contained 4 g of 1-chloroheptafluoropropane and 236 g of 1,3-diohlorhexaf luoropropane and 17 g of unreacted 1,1,3-trichloropentafluoropropane contained.

-16- 809812/1415

Claims (2)

1. ELuorierungsverfahren _8, characterized in that @ in @ a mixture of 1 _B 1.1 _s 3 $ 3 ' ₉ 3 * -Hexg.ehloröif luorpropane and hydrogen fluoride in the equivalent of a chromium oxide catalyst is heated to 200 to 500 ° and the product I ₉ 3 -331 ohlorhexa- fluoropropane wins _a ■ 2. ' Ancestors according to claim 1 _D, characterized ₉ that one is made from miiohung. 1 _s 1,1 ₉ 3 ₁ 3- »3-; H © 3sachlorodifluoropropane and! Hydrogen fluoride over an ear modulator of 200 - up to 500 ° © rhitat and ®in © mixture.aua 1.1, 1 _s 3 ₉ 3 «P © nta · = · oßlort rif luoropropane. ₉ V ₉ 1. _e 3i5 ~ 2etr & öhlort © "met luorpropane * 1 j T _s 3- = Srißhl © rp © ntaf luorpropane ₉ 1 ^« Diohlorhexaf luorpropane and I-chloro ^ heptafluorpropane wins. _o 3β T © rfshr @ n according to claim 2 characterized gekennzelohne _S t ₉ that the -1 ο 1> 1 £> 3 9 5 = - r P®ntaehlort ±± luorpropan ₉ 1 ₉ 1 _B 3 _3-f T®traohlo2? i; ®trafluorpropane and the 1 _ff 1 _s 3 ~ SriöhIorp®ntsfluorpropen in di® B@schiokungsmisch.ung surüc! kg © leads be _β üaoh claim 2 uiad 3
4. Process ^ characterized by the fact that one! Hydrogen fluoride 91o 3 3 3-3? Entachlort rif luoropropane j 1 ₉ 1 ■ ₉ 3 ₉ 3 = »inetrachlor · = ·" t straf luoropropane - or 1- ₉ 1 ₉ 3- = trichloropentaf luoropropane at -. A temperature between 200 and 500 ° ffiit a Chromoayd 80 9812 / 1415-- catalyst brings into contact and 1,3-Eichlorhexafluorpropane and 1-chloroheptafluoropropane is obtained as the product. Fluorination-5 * / process, characterized in that a mixture of propyne and hydrogen fluoride with a chromium oxide catalyst - sator in contact at a temperature between 75 and 400 ° brings and receives as product 2,2-difluoropropane. $ · Process for the preparation of 1,3-bichlorohexafluoropropane, optionally mixed with 1-chloroheptafluoropropane, characterized in that a mixture of 1,1,1j3 »3 _f 3 · hexaohlordifluoropropane and hydrogen fluoride is heated to 200 to 500 ° in the presence of a chromium oxide catalyst heated and obtained from the reaction product 1,3-dichlorohexafluoropropane and possibly 1-chloroheptafluoropropane » 7 * procedure NaOH claim 6, characterized gekennsaichnei "DAB one daa in E ^e reaction product contained 1,1,1,3» 3 Pentachlortrifluorpropan and / or 1,1 ^ 3,3 '-3Detrachlortstrafluorpropan and / or 1,1, 3- £ richlorpentafluoropropane returns to the reaction mixture. Dar patent attorney 809812/1415 original inspected